Biometric identification methods are ubiquitous and have been employed in many areas as a means of ensuring security through personal verification. Established biometric identification methods include the use of fingerprints, hand geometry, iris, retina, voice recognition, handwriting etc. Kumar et al (2003) identify limitations to the reliable use of some of these methods due to difficulty acquiring the necessary details to make correct verifications, or due to logistical problems in employing the method of verification in the same manner each and every time.
Wadia (U.S. Pat. No 4,720,869) and Sidlauskas (U.S. Pat. No 4,736,203) have explored the use of hand surface geometry for the purpose of biometric identification. Wadia's use of a two-dimensional optical scanner to process the data to develop invariable hand measurements, and Sidlauskas' use of a digitizing camera and a pair of orthogonal reflecting surfaces to obtain a three-dimensional image of a hand have both been successful methods for identification. However, since the application of these methods rely on the soft-tissue dimensions of the hand, these methods are limited by the potential environmental and physiological factors that may alter the dimensions of the surface of the hand. Moreover, trials with this methodology have revealed that it is possible to falsify authentication. Therefore, the proposed invention aims to eliminate such consequential details by focusing attention on the bone structure of the hand.
Traditionally, plain radiographs, CT, and MRI have been used to evaluate the hand and wrist. However, recent advances in technology have allowed ultrasound to be considered one of the first line imaging techniques in the assessment of this entity (Bianchi et al, 2001; Teefey et al, 2000). Ultrasound is an attractive option to analyze bone geometry because it is inexpensive, non-invasive, rapid and lacks the radiation exposure that often accompanies the traditionally preferred modalities (Danese & Licata, 2001).
The method of biometric identification of an individual based on ultra-sound scan analyses of hand bones is unique in its own characteristics, and attempts to overcome the limitations suggested by Kumar et al (2003). This new method uses a very inexpensive and safe means to acquire the data via ultra-sound scanning of the hand bones. Research has established that trabecular bone architecture is unique to each individual and stable enough to be used as a means for positive identification (Kahana et al, 1998; Kahana & Hiss, 1994). Therefore, this new method attempts to identify an individual based on his/her hand bone geometry, because hand bones are unique to each person, and because the method to acquire the data is inexpensive, safe, accurate, and a non-invasive tool.